The proposed Center Grant is a request for continued CIRID funding of an ongoing Center for Interdisciplinary Studies of Immunology at Georgetown. The Center exists as a functionally recognized unit of the University and has integrated programs in research, education and patient care, as well as in community, outreach, technology transfer and education. The overall proposed program project consists of senior investigators representing basic science and clinical disciplines (pediatrics, medicine, neurology, biochemistry, microbiology, biostatistics, and community medicine) all of whom have pooled their expertise and resources in the present CIRID grant proposal. The present proposal has been significantly revised and has been prepared as a program project grant and includes five interrelated, interdependent research projects. Four of the project (1-4) interact around a central unifying theme of maturational immunologic processes in the developing host and their role in antimicrobial host defense. The broad hypothesis to be examined is that deficiency or impairment in development in any of a number of nonspecific and specific immunologic parameters can lead to immunologic compromise and predispose the developing host to severe infection and disease. The projects range from studies of the development of phagocytic function in the neonate (Project 1), structural and functional studies of the third component of complement (Project 2), developmental studies of the secretory IgA system (Project 3), studies of the developing immune system on responses to viral and myelin antigens (Project 4); a fifth project community outreach technology transfer and education includes a pediatric asthma patient education project utilizing self-management techniques.